Propagation analysis of plasmaspheric hiss using Polar PWI measurements

Abstract

Abstract. We have analyzed high-rate waveform data, taken Storey et al. [1991] however observed hiss emissions even by the POLAR Plasma Wave Instrument at high altitudes in when, after long periods of magnetic calm, the plasmapause the equatorial plasmasphere, to study plasmaspheric hiss in the was absent. They also found that the waves often propagate at range of frequencies between 100 Hz and several kHz. These large angles from B0, even in the equatorial region. This means emissions are found almost everywhere in the plasmasphere, these waves cannot be generated exactly in the way Kennel and their origin is still controversial. Our analysis of several and Petschek [1966] suggested. These results do not directly cases shows that most of the waves were propagating more or contradict the theory of Thorne et al. [ 1973, 1979], but they do less parallel to the Earth's magnetic field, but sometimes a few suggest that under certain circumstances some other mechanism of them were propagating obliquely with their normals near may be acting. Indeed, highly oblique wave propagation fits a the Gendrin angle. Evidence of amplification was found near theory developed by Draganov et al.

Plasmaspheric hiss overview and relation to chorus

“…This is illustrated in panels (b)-(d), where the ray undergoes a well-defined sequence of reflections and equatorial crossings in the order: (MR-EQ-MR)-(PR-EQ-PR)-(MR-EQ-MR)-, etc. Panel (d) shows that whenever the ray crosses the equator, its wave normal angle is roughly field-aligned (an integer multiple of 1801), in agreement with recent observations that have indicated that plasmaspheric hiss occurs with roughly field-aligned wave normal angles (Santolik et al, 2001).…”

Review of modeling of losses and sources of relativistic electrons in the outer radiation belt II: Local acceleration and loss

“…The first row shows the computed pitch-angle diffusion coefficients using the assumption of parallel propagation for the specified energies. The assumption of parallel propagation is justified by the case study of Santolik et al (2001). In addition, comparison of simulations with various assumptions of wave-normal angle distributions show that the observed scattering rates are best reproduced in simulations using small wave-normal angles, indicating that the waves are predominantly field-aligned .…”

Relativistic electron acceleration during HILDCAA events: are precursor CIR magnetic storms important?

“…We use continuous measurements of the Spatio-Temporal Analysis of Field Fluctuations-Spectrum Analyzer (STAFF-SA) instrument (Cornilleau-Wehrlin et al 1997). The presence of whistler-mode emissions is identified from the measured power-spectral densities and from analysis of the wave polarization (Santolik et al 2001. High-resolution waveform observations of the Wideband Data (WBD) instrument ) have been used to verify presence of the discrete frequency-time structures of chorus wave packets (Santolik et al 2014b).…”